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FLORIANÓPOLIS

WORKSHOP MIT - Model Cities Anywhere - Pathways towards a Net-Zero Building Stock

January 2021

This presentation has been updated for clarity by the MIT Sustainable Design Lab in December 2022

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Downtown area

Residential

Office

Educational

Restaurant

Snack bar

Night Club

Retail

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93 Buildings

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Climate

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Questions

  1. Energy efficiency / Passive strategies (retrofitting): how much energy could we save if adopted a certain package of strategies?

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  • Generation / Photovoltaics: would it be significant? Constraints: high density (+shading), roof area.

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Assumptions made

  • Heating only enabled for Residential Archetypes
  • Domestic Hot Water Disabled
  • Hybrid Natural Ventilation and Mechanical Systems for Residential, Restaurant and Retail Archetypes
  • Office Archetypes use only Mechanical Systems

Costs heating fuel [US$/kWh]

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Costs cooling fuel [US$/kWh]

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Costs electricity fuel [US$/kWh]

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Costs hot water fuel [US$/kWh]

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CO2e emissions heating fuel [kgCO2e/kWh]

0.09

CO2e emissions cooling fuel [kgCO2e/kWh]

0.09

CO2e emissions electricity fuel [kgCO2e/kWh]

0.09

CO2e emissions hot water fuel [kgCO2e/kWh]

0.09

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Office

Restaurant

Residential

Retail

UMI Model

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Energy efficiency / Passive strategies (retrofitting)

  • Light colors on walls and roofs (abs ~0.39 considering aging);

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  • Better glazing (SHGC from 87 to 39);

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  • Shadings;

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  • Improved roof (insulation).

Focus on Cooling Loads

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Initial results

Total energy doesn’t change much (focus on cooling)

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Cooling results

-21%

-24%

-28%

-38%

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Initial results

Consumption in Restaurants is significant (equipments should be addressed)

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Energy use with PV

2.7 GWh reduction through PV

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Emissions with PV

Emission factor: 0.09

240,000 kgCO2e reduction through PV

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District Energy Consumption Costs

Total Savings for the district:

more than $100,000/year = 540,000 Real/year

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Conclusions

  • Energy efficiency / Passive strategies (retrofitting): how much energy could we save if a certain package of strategies is adopted?

Up to 38% of the cooling loads

  • Generation / Photovoltaics: would it be significant? Constraints: high density (+shading), roof area.

Yes, it can be significant

  • Shadings vs. Lighting: Does glazing have an impact? Lighting loads increase but cooling loads are dramatically reduced.

Yes, it is essential, especially shading to reduce city wide temperatures

  • Equipments in Restaurants: Equipments produce too much latent heat loads.

Increase efficient lighting or improved equipments = Major Energy Savings $$$ + CO2 !